Mexico City is drinking itself into the ground

Mexico City's cathedral, which had to be propped up with stone wedges as it was being built to stop it sinking. Image: Francisco Diez

When the Aztecs founded the city of Tenochtitlán in the middle of a lake, they thought they were being incredibly clever.

It was 1325, the height of the era of Mesoamerican tribes vying for supremacy in the narrowing strip between the Pacific Ocean and the Caribbean Gulf, and a small island on the western side of Lake Texcoco seemed like a pretty good place to be. 

The Mexica people who lived there – and from whose tribe the name Mexico now comes – became enormously successful. Their Aztec Empire was the most formidable force on the continent, exerted control and influence for thousands of miles around, and established trading relationships stretching as far as the Inca Empire in modern-day Peru.

Their island city, smattered with canals, causeways, and dykes, was a lesson in sustainability.

Lake Texcoco and the city of Tenochtitlán before s*** went down. Image: Yavidaxiu.

The channels they built provided natural irrigation and water management, while floating gardens called chinampas kept the city fed as it grew to an astonishing size. By the time the Spanish conquistadores arrived in the 16th century, the city had approximately 300,000 residents – making it five times the size of London at the time.

The Mexico City of today is a very different story.

A choked-up Mexico City today. Image: Fidel Gonzalez/creative commons.

Up no creek with no canoe

A choking, smog-shrouded sprawl of 21m people. It has no island, no lake, a water shortage that means millions are left with empty taps on a regular basis, and is sinking at an astonishing rate.

Roughly 20 per cent of Mexico City’s residents cannot guarantee that water will come out of their taps every day, and the ground is sinking by as much as nine inches a year in some suburbs. That’s the equivalent of nearly a storey a decade.

The city’s cathedral, which took more than 200 years to build, has a leaning chapel and bell tower, propped up by stone wedges to stop the whole thing crumbling down. The Gilded Angel of Independence – a local tourist hotspot and national landmark – was built with nine shallow steps leading up from the street below. As the surrounding area has sunk, an extra 14 large steps have been added as the angel is increasingly left marooned above a vanishing city.

Slanted buildings leer menacingly over pavements, their doors and windows no longer in alignment with their friends as if crudely displaced from a grotesque theme park funhouse. Terraced streets built on level ground now undulate, with wavy gables crowding up against each other in parts, and pulling away in others, while city-dwellers struggle up hilly pavements where once the path was flat.

In Iztapalapa, a suburb of approximately 2m people built on the ancient lake’s southern shores in the city’s south-east, 15 primary schools have crumbled or caved in, and a teenager was swallowed up when a gaping crack appeared in the street.

So what happened?

As per usual, the blame can be placed squarely on the shoulders of the pesky European invaders.

Xochimilco, the last vestige of Mexico City's lakeside history. Image: Owen Prior.

Veni, vidi, conquistadori

When Hernán Cortes entered the city in 1519, he was “stunned by its beauty and its size”, and in awe of a city where he was welcomed as a god and given plush lodgings by the Aztecs. This, obviously, did not last: war ensued, and the conquistadores took control of the city and named it the capital of their new colony, the Viceroyalty of New Spain.

Where the Aztecs had constructed dykes and channels to live in harmony with the lake, the Spaniards covered them over to build roads and increase the city’s size. They started draining the lake and cutting down the forests on its shores, making the city more susceptible to intense flooding.

Mexico City suffered major floods in 1555, 1580, 1604, and 1607, before one bright spark proposed moving the capital to dry land in 1630. But after deliberating on this for a while, the authorities decided that the answer was no, and the flooding continued, with more serious deluges in 1645, 1674, 1691, 1707, 1714, 1724, 1747, and 1763.

One flood was so severe that the entire city was submerged for five whole years from 1629 – yet the city lived on, gasping for air and expanding further across the lakebed between downpours.

By the 20th century, most of the lake had been drained, and flooding became the least of the city’s worries. As it grew and grew, and poorer migrants from the surrounding country arrived in search of economic opportunity, Mexico City grew thirsty.

Which was a problem.

The Gilded Angel of Independence, which has risen above the sinking streets. Image: TJ DeGroat.

Geologically insane

The city is built on two different geological foundations. Some of the ground underneath Mexico City is volcanic soil, which was fertile and used by the Aztecs for growing crops. It was also handily water-absorbent: moisture would soak in and flow to underground aquifers easily, without damaging the structure of the soil.

But when developers built on the volcanic soil and covered it in concrete and asphalt, water could no longer get through to the soil and filter through to the aquifers on which the city relies. And other parts of the city sit on clay. This, unlike the volcanic soil, can't absorb the water, merely sandwiching it between layers of clay – like cream between layers of pastry. When the cream is sucked out, the layers of pastry crack and collapse, falling on top of one another.


And that’s what’s happened beneath Mexico City. Desperate for water in a lake basin devoid of a lake, the city has tapped into the clay soil while covering over the useful volcanic soil. And as the city is built on a mixture of both geologies, it has sunk in an uneven, mismatched way, causing dangerous fissures, cracks, and the bizarre phenomenon of wavy, undulating streets.

It is estimated that the city has dropped 10 meters in the last century; if anything the signs are that this process is accelerating.

The climate change doom blockbusters show us coastal cities dramatically engulfed by storms and waves from rising sea levels, as great ice shelves melt in the Arctic and Antarctic.

But one of the first cities claimed as victims by man-made destruction may be less cinematic: a leviathan of 21m sinking into the ground, cracking and buckling, swallowing up people, houses, and livelihoods, and starving its poorest residents of water and hope as it goes. 

Jack May is a regular contributor to CityMetric and tweets as @JackO_May.

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How the pandemic is magnifying structural problems in America's housing market

Justin Sullivan/Getty Images

Long before Covid-19, the United States suffered from a housing crisis. Across the country, working class and low-income Americans struggled to pay rent, while the possibility of home ownership receded into fantasy. In hot markets, affordability became a struggle for even the middle class: In California, 41 percent of the population spends over a third of their income on housing costs. 

The coronavirus pandemic will only make these trends worse as millions are unable to work and the economy dives into a recession. Building could slow down in the medium term, as construction loans (risky bets in the best of times) become harder to come by. Unsubsidised affordable housing is often owned by small landlords, who are more likely to struggle during recessions, prompting flips to home ownership or sales to rental empires. 

New York Times reporter Conor Dougherty documented America’s longstanding housing crisis – and California’s efforts to battle it – in his book Golden Gates, which debuted just before the pandemic hit. “My sense is that right now coronavirus is magnifying a lot of things that were already happening,” Dougherty says.  


While Covid-19 adds new pressures, he says that many of the same issues we were facing still loom over the issue, from developers crowding the higher end of the market, to escalating construction costs, to stagnating wages and vulnerable service-sector jobs that leave ordinary Americans struggling to keep a roof over their heads. “That’s my larger message,” Dougherty says. “I think the structural problems continue to be a much bigger deal than the cyclical problem in housing.”

CityMetric spoke with Dougherty about how his thinking has changed since Covid-19, Donald Trump’s pro-suburban rhetoric, and the apparent exodus from San Francisco. 

I’ve really been struck by how strong the housing market seems to be despite the epic economic crisis we are facing. Costs seem to be higher everywhere. I've heard realtors talk about bidding wars like they haven't seen before in Philly, where I live. But perhaps that's just pent up demand from the big shutdowns?

What you have is an economy that has bifurcated. You have fewer middle-income jobs, more lower-income service jobs, and more higher-end jobs in software and finance. That's how our economy looks and that's a problem that is going to take the rest of our lives to solve. In the meantime, we have this housing market where one group of people have so much more money to spend than this other group. Cities reflect that. 

What's important about this bifurcation isn't just that you have gross inequality, but that these people have to live next to each other. You cannot be someone's Uber driver and telecommute. You cannot clean someone's house remotely. These lower-end service workers have to occupy the same general housing market as the super-high-end workers. 

All the pandemic has done is thrown that even more out of whack by creating a situation where one group of people is buying and expanding homes or lowering their home cost by refinancing, while another group are at income zero while trying to live in the same housing market with no demand for their services. When you see home prices booming and an eviction tsunami coming in the same newspaper, that tells you the same thing the book was trying to show you.

Does America writ large have the same housing shortage crisis as California and the Bay Area more specifically? There are other super hot markets, like New York City, Boston, or Seattle. But in Philly, or in Kansas City, is there really a lack of supply? 

There are three kinds of cities in America. There are the really out of control, fast-growing, rich cities: the Bay Area, Seattle, New York. There are declining Detroits and Clevelands, usually manufacturing-centric cities. Then there are sprawling Sun Belt cities. This book is by and large concerned with the prosperous cities. It could be Minneapolis, it could be Nashville. But the housing crisis in places like Cleveland is much more tied to poverty, as you pointed out. 

Those kinds of cities do have a different dynamic, although they still do have the same access to opportunity issues. For instance, there are parts of Detroit that are quite expensive, but they're quite expensive because that's where a lot of the investment has gone. That's where anybody with a lot of money wants to live. Then you have Sun Belt cities like Dallas and Houston, which are starting to become a lot more expensive as well. Nothing like the Bay Area, but the same forces are starting to take root there. 

I think that the Bay Area is important because throughout history, when some giant American industry has popped up, people have gone to Detroit or Houston. Now tech, for better or for worse, has become the industrial powerhouse of our time. But unlike Detroit in its time, it's very hard for people to get close to and enjoy that prosperity. There's a certain kind of city that is the future of America, it has a more intellectual economy, it's where new productive industries are growing. I think it's an outrage that all of them have these housing crises and it's considered some insane luxury to live there. 

A recent Zillow study seemed to show there hasn't been a flood of home sales in the pandemic that would signify a big urban exodus from most cities, with the glaring exception of San Francisco. Do you think that could substantially alleviate some of the cost pressure in the city proper?

On the one hand, I think this is about the general economy. If unemployment remains over 12% in San Francisco, yes, rent is going to be a lot cheaper. But is that really the reality we're all looking for? If restaurants and bars that were key to the city's cultural life remain shut, but rent is cheaper, is that what everyone wants? I bet you when this is all over, we're going to find out the tech people left at a much lower rate than others. Yes, they can all work from home, but what do you think has a bigger impact on a city: a couple of companies telling people they can work from home or the total immolation of entire industries basically overnight?

I don't want to make predictions right now, because we're in the middle of this pandemic. But if the city of San Francisco sees rents go down, well, the rent was already the most expensive in the nation. It falls 15%, 20%? How much better has that really gotten? Also, those people are going to go somewhere and unless they all move quite far away, you're still seeing these other markets picking up a lot of that slack. And those places are already overburdened. Oakland's homeless problem is considerably worse than San Francisco's. If you drive through Oakland, you will see things you did not think possible in the United States of America. 

Speaking of markets beyond San Francisco, you have a chapter about how difficult it is to build housing in the municipalities around big cities – many of which were just founded to hive off their tax revenues from low-income people.

That’s why you see Oregon, California, or the Democratic presidential candidates talking about shaking this up and devising ways to kick [zoning] up to a higher level of government. We've always done this whenever we've had a problem that seems beyond local governance. Like voting rights: you kick it to a higher body when the local body can't or won't solve it. 

But for better or for worse, this suburban thing is part of us now. We cannot just undo that. This notion of federalism and local control, those are important American concepts that can be fiddled with at the edges, but they cannot be wholesale changed. 

The first time I ever met Sonja Trauss [a leader of the Bay Area YIMBY group], she told me she wasn't super concerned about passing new laws but that the larger issue was to change the cultural perception of NIMBYism. We were living in a world where if you went to a city council meeting and complained about a multifamily development near your single-family house, you were not accosted for trying to pump up your property values or hoard land in a prosperous city. You were seen as a defender of the neighbourhood, a civically-minded person.

What is significant about YIMBYism is that the cultural tide is changing. There is this whole group of younger people who have absorbed a new cultural value, which is that more dense housing, more different kinds of people, more affordable housing, more housing options, is good. It feels like the tide is turning culturally and the movement is emblematic of that. I think that value shift will turn out to have been much more lasting than anything Scott Wiener ever does. Because the truth is, there are still going to be a bunch of local battles. Who shows up and how those places change from within probably will turn out to be more important. 

As you said, we've been seeing a lot of Democratic candidates with proposals around reforming zoning. How does Joe Biden's plan compare to the scope of the ambition in the field? 

There are two big ideas that you could pull from all the plans. First, some kind of renter's tax credit. It is obscene that we live in a country where homeowners are allowed to deduct their mortgage interest, but renters aren't. It is obscene that we live in a world where homeowners get 30-year fixed mortgages that guarantee their house payment pretty much for life and renters don't. If we think that it's a good idea to protect people from sudden shocks in their housing costs, that is as good of an idea for renters as it is for homeowners. 

I tell people that in this country, homeowners are living in the socialist hellscape of government intervention and price controls. Renters are living in the capitalist dream of variable pricing and market forces. Homeowners think they're living in this free market, but actually they're in the most regulated market – there are literally price controls propping up their market mortgages. 

Then there is Section 8 housing. Right now homeowners get access to the mortgage interest deduction. That programme is available to as many people as can use it, yet only about a quarter of the people eligible for Section 8 can get it. I think rectifying that is hugely important and a lot of the plans talked about that. 

The second big idea is using the power of the purse to incentivise people to more robustly develop their regions. You should have higher density housing in fancy school districts, near job centres, near transit. We're going to use the power of the purse to incentivise you, within the bounds of your own local rules, to do this right. Of course, that’s what Donald Trump is running against when he talks about Affirmatively Furthering Fair Housing (AFFH). 

When I was a local reporter in Philly, the city went through with that AFFH regulation despite Trump and HUD Secretary Ben Carson not being interested in enforcing it anymore. The city produced a fat report that maybe a few people read, but I don't think it changed policy. It's this phantom that Trump is running against, an ideal version of the policy that did not exist. It's also a phantom no one's heard of until Trump started tweeting about it. 

It’s been bizarre to watch. But Trump does seem to recognise that suburban politics don’t neatly fit into a red or blue construct. People who live in Texas and claim to want a free market system will turn around and erect local regulation to make sure nobody can build apartments near them. People in the Bay Area who claim to be looking for a more diverse place will use different logic, anti-developer logic, to keep apartments being built near them. 

People like that regardless of how they feel about things nationally. The bluntness with which Trump is doing it is discordant with the electorate and quixotic because people don't know what he's talking about. But the basic things he recognises – can I make voters feel like their neighbourhoods are threatened – he's onto something there. As with many things Trump, his tactics are so off-putting that people may ultimately reject them even if under the surface they agree.

You hear people on the left say the scary thing about Trump is that one day a good demagogue could come along. They're going to actually tax private equity people and they're actually going to build infrastructure. They're going to actually do a lot of popular stuff, but under a racist, nationalist banner. I think the suburban thing is a perfect example of that. There's a lot of voters even in the Bay Area who [would support that policy] in different clothing.

The world has changed completely since Golden Gates debuted just a few months ago. Has your thinking about housing issues changed as a result of the seismic disruptions we are living through?

The virus has done little more than lay itself on top of all of the problems I outline in the book. Whether we have an eviction tsunami or not, a quarter of renters were already spending more than half their income on rent. There's a chapter about overcrowded housing and how lower-income tenants are competing with each other by doubling, tripling, and quadrupling up for the scant number of affordable apartments. We now know that overcrowded housing is significantly more of a risk [for Covid-19] than, say, dense housing. If you live in a single-family home with 15 people in it, that's a lot more dangerous than 40 apartments in a four-story building.

Housing is just a proxy for inequality, it's a way of us building assets for one group at the exclusion of another. It is an expression of the general fraying of American society. I don't feel like that larger message has been affected at all, it's only been enhanced by the pandemic. With the caveat that this can all change, it just doesn't seem to me like there's some uber housing lesson we can learn from this – other than having a bunch of people crowded together is a really bad idea. 

Jake Blumgart is a staff writer at CityMetric.